Control mechanism for textile machinery



y 21, 1968 K. WRIGHT 3,384,125

CONTROL MECHANISM FOR TEXTILE MACHINERY Original Filed Oct. 28, 1965 5 Sheets-Sheet 2 May 21, 1968 K. WRIGHT CONTROL MECHANISM FOR TEXTILE MACHINERY 5 Sheets-Sheet 3 Original Filed Oct. 28, 1965 United States Patent 3,384,125 CONTROL MECHANISM FOR TEXTILE MACHINERY Kenneth Wright, Coalville, England, assignor to Clutsom & Kemp Limited, Coalville, England, a British company Continuation of application Ser. No. 505,504, Oct. 28, 1965. This application Oct. 20, 1967, Ser. No. 676,980 Claims priority, application Great Britain, Oct. 28, 1964,

43,884/ 64 8 Claims. (Cl. 139-66) ABSTRACT OF THE DISCLOSURE A loom dobby mechanism for timing the lifting and lowering movements of healds under patterning control, characterized by the absence of return springs and including a row of drivers disposed on either side of a set of heald shafts, one of each row being engageable and disenagageable with one of the heald shafts, to lift and lower the latter, cam controlled driving levers for vertically reciprocating the drivers, opposed control means for engaging and disengaging said drivers with and from said heald shafts and locking means for holding heald shafts in their raised positions.

This application is a continuation of Ser. No. 505,504, now abandoned.

This invention relates to automatic mechanisms for incorporation in textile machines for effecting and controlling the movements of components requiring to be shifted up and down or back and forth from one position to another, or to be allowed to pause or dwell for variable lengths of time between strokes, according to patterning requirements.

Mechanisms according to the invention are primarily intended for use as dobby mechanisms in looms for effecting the timing of the lifting and lowering movements of healds under patterning control.

A weaving loom is customarily provided with a series of vertically slidable heald shafts connected respectively to the healds and adapted to be lifted under the control of a dobby mechanism, and dropped individually in a predetermined order to produce a desired Woven pattern.

In the conventional form of dobby mechanism either an endless chain (furnished with pre-arranged control bits, pegs or lugs), or a punched card, effects the operation of levers which, through various motion-transmitting means, raise jack levers associated with the heald shafts. The form of the motion-transmitting means limits the speed of operation of the dobby mechanism and the loom. Each of the heald shafts can only be shifted in a positive manner when being raised, a spring or the force of gravity being relied on to assist in the return of a heald shaft to its low position. Such means are insufficiently .positive to prevent bouncing and vibration of the heald shafts at speed.

An object of the present invention is to provide a loom dobby mechanism characterised by an improved motion transmitting means and by the absence of springs and so designed as to enable both the forward, e.g. lifting, and the return, movements the heald shafts to be effected positively, thereby eliminating bounce and vibration.

An aim is to provide a loom dobby mechanism which can be operated at substantially higher speeds than are normally possible, i.e. speeds of the order of a thousand picks per minute.

A general aim is to provide an improved, inexpensive and efiicient control mechanism for selectively actuating at high speed and determining, under control, the timing of rectilinear movements of a series of components requiring to be moved up and down or to and fro.

3,384,125 Patented May 21, 1968 The control mechanism according to this invention includes a plurality of drivers, two of which are adapted to be associated with, and respectively flank opposite sides of, each of a, plurality of shafts or bars connected directly or indirectly respectively to a series of components to be controlled by means of which each of the components can be shifted rectilinearly from one position to another and back again, according to patterning requirements, each of the shafts and its associated drivers having complementary formations, the drivers being movable laterally, i.e. transversely to the shaft, to bring the complemenray formations into and out of engagement whereby the relevant shaft can be engaged by either one driver or the other, and each of said drivers is capable individually of advancing or retracting the relevant shaft.

Advantageously, the two drivers associated with each shaft are reciprocated in paths parallel to the paths of the movement of the shaft and the drivers move through identical strokes at the same speeds and are one stroke out of phase, so that when one driver is in the advanced position the other driver is in the retracted position.

Each shaft can be shifted from one position to another position by one or other of the drivers and may then be immediately retracted to the first position by the same driver or, alternatively, may be disengaged from the driver and remain in the second position and be subsequently engaged With either the same driver or the other driver and be retracted to the first position upon a subsequent retraction stroke of the relevant driver. In some applications of the control mechanism the components will require to be moved vertically from a low position to an upper position and then back again to the low position.

In this case by leaving a shaft in engagement with either one of the two associated drivers for a prolonged period of time that shaftand the associated component will be vertically reciprocated throughout the period but can be engaged and disengaged as required. By a judicious set out of the control means, the components to be controlled can be moved up or down variously and in contrasting sequences relatively to one another according to patterning requirements.

The two drivers associated with each shaft are guided for movement along said paths by any appropriate means, for example are slidable on rods supported. by a common frame extending in a plane coincident with or adjacent the path of movement of the shaft. The two drivers associated with each shaft are arranged to be selectly engaged with the relevant shaft by shifting the frame, in one direction or the other (from a neutral position in which neither driver is engaged with the shaft) in the plane of the frame transversely to the path of movement of the shaft by control means.

The mechanism preferably includes means for locking or holding each of the shafts in its upper or lower position at appropriate times.

The drivers are arranged to be reciprocated by any suitable means such as a pair of levers, arranged one on each side of the row of shafts, pivotally mounted adjacent one end, and being articulated to the drivers and adapted to be oscillated about the pivot by means of cams driven in timed relationship.

In one embodiment, each shaft has two recesses formed in each of its opposite edges and each driver is in the form of a forked yoke, the two limbs of which are shaped to engage the recesses in the shaft, the levers for removing the yokes each passing between the limbs of the yokes.

Each frame is supported and movable by a pair of levers, disposed at opposite sides of the frame, and each pivoted at one end to the frame and at the other end to suitable supports.

These levers are turned by control means which may be electrically or electronically and hydraulically operable and/or comprise punched cards. Preferably, the control means are in the form of control cams. Thus they may be of similar form to those conventionally employed for controlling control mechanisms and comprising two endless chains furnished with cams and located at opposite sides of the shafts. However, such chains have to be of lengths corresponding to the length of the pattern and of a width to control all shafts and are expensive.

Accordingly, the control means may comprise two sets of rotary cams, controlling respectively the levers of opposite sides of the frame, the cams of each set being mounted upon a common shaft.

Preferably, however, in accordance with a feature of the invention there is provided control means comprising two endless chains furnished with cams and arranged at respectively opposite sides of and to control each of some only of the shafts and two individual rotary cams arranged at respectively opposite sides and to control each of the remaining shafts.

The chains control only those of the shafts associated with the components for producing the pattern in the fabric, those of the shafts associated with the components for producing the plain or simply patterned background of the fabric being controlled by the individual rotary cams. Since the chains control some only of the shafts they are narrower, and less complex and expensive than those provided hitherto and the rotary cams additionally required are not expensive.

One specific example of the control mechanism in the form of a loom dobby mechanism will now be described with reference to the accompanying drawings, where:

FIGURE 1 is a part sectional perspective view showin the principal parts of the mechanism.

FIGURE 2 is a partial end elevation of the mechanism, and

FIGURE 3 is a vertical cross section taken on the line IIIIII of FIGURE 2.

The mechanism of this example is partially located within a casing 1 and as shown includes a row of eight vertical shafts 2, each of which is connected directly or indirectly to the relevant one of a series of heald frames (not shown) to be raised and lowered for patterning. If desired, two further shafts (not shown) may be provided at one end of the row, these being arranged to be regularly reciprocated vertically to shed the warp threads.

The shafts 2 are of fiat cross section and are mounted for vertical sliding movement in upper and lower bearings comprising banks of plates 3, 4, rigidly fixed upon supports 5 by means of bolts 6. The alternate plates 3 are formed with recesses 3a to receive the shaft 2.

A rectangular frame 7 is associated with each of the patterning shafts 2 and its median plane is located in a vertical plane coincident with the median vertical plane of the shaft. Thus each of the upper and lower horizontal portions 7a, 7b, of each frame are formed with identical apertures 70, 7d of a width approximately equal to the thickness of the shaft and of a length in excess of the width of the shaft. Each frame 7 is mounted upon the relevant shaft 2 such that the shaft can be moved vertically relatively to the frame and the latter can be moved laterally, i.e. horizontally in its vertical plane, relatively to the shaft 2. The portions 7a, 7b of each frame are each formed with a recess which is closed at one side by a plate 8 secured thereto so as to define the apertures 70, 7d.

Each of the shafts 2 has two identical rectangular recesses 2a formed in each of its opposite longitudinal edges, at an appropriate distance apart, the recesses in one edge being aligned with those in the opposite edge. The disposition of the recesses is the same in all the shafts of the row. Each shaft is also formed, upon one side face and centrally of the width thereof, with four rectangular projections 9, 10, 11 and 12 spaced apart vertically.

Two rows of drivers, i.e. forked yokes 13 and 14, are disposed at opposite sides of the row of shafts 2, one driving yoke of each row being associated with the relevant one of the shafts 2 and being located within the confines of the associated frame. Each yoke 13, 14 comprises a portion 15, 16, from which extends two vertically spaced horizontally extending identical limbs 17, 18, of rectangular cross'section greater than the thickness of the shaft. The limbs of each yoke are so spaced apart that they can be engaged with the two recesses 2a in the relevant edge of the associated shaft 2. The two yokes 13, 14, associated with each frame 7, are mounted for vertical reciprocation respectively upon two rods 19 extending within and adjacent the vertical portions of the frame. Each limb of each yoke is formed at the end with a recess 17a, 18a, of rectangular form and of a width corresponding to the thickness of the shaft 2 so that each limb is forked at its leading end. The two portions 17b, 18b, defining the fork straddle the edge of the shaft 2, even when the limbs are disengaged from the recesses 2a, as clearly shown in FIGURES l and 2, so that although the shaft is free to move vertically the yoke is prevented from turning about the rod 19.

The two sets of yokes 13, 14 are arranged to be vertically reciprocated by means of two driving levers 20 each extending between the limbs of the yokes as shown in FIGURES 1 and 2.

The levers 20, are pivotally mounted adjacent one end upon a pivot pin 21 (FIGURES 1 and 3) so that they can be swung up and down independently of one another. Two eccentrics 20a are mounted upon a common horizontal drive shaft supported by bearings within two housings and are surrounded by straps connected to the levers whereby the latter are raised and lowered. The two levers move through identical strokes at the same speeds and are one stroke out of phase, so that when one lever is in the upper position, the other is in the lower position.

Each frame 7 is arranged to be selectively moved between a position in which one of the relevant yokes 13, 14 is engaged with and drives the associated shaft 2, another position in which the other yokes 13, 14 is engaged with and drives the shaft, and an intermediate neutral position (shown in FIGURES 1 and 2) in which the shaft is not engaged by either yoke.

Each shaft 2 can be held at appropriate times in either its upper or its lower position to which it has been moved by the relevant driving yoke and then released by that yoke. The plates 8 at the upper and lower portions 7a, 7b of each frame 7 are each formed with two small slots 8a, 81) disposed at equal distances to opposite sides of the vertical axis of the frame 7 and of a size to enable the upper and lower projections 9 and 12 upon the relevant shaft 2 to pass therethrough.

When the shaft is moved between its upper and lower positions by the yoke 13 the projections 9 and 12 pass respectively through the slots 8a in the upper and lower plates 8; and when the shaft is moved between its upper and lower positions by the yoke 14 the projections 9 and 12 pass through the slots 811. When the shaft is to be retained in its upper position the frame 7 is moved by the control means to disengage the shaft from the relevant yoke into a neutral position in which the upper projection 9 abuts against the upper side of the portion of the plate 8 between the slots, as shown in FIGURE 2. The projection 10 abuts against the underside of the portion 80 to prevent the shaft being inadvertently moved up wardly beyond its normal upper position. When the shaft is to be retained in its lower position the frame 7 is moved to disengage the shaft from the revelant yoke into a neutral position (shown in FIGURE 1) in which the lower projection 12 abuts against the underside of the portion 8c of the lower plate 8 between the slots. Projection 11 abuts against the upper side of the portion 8c of the lower plate to prevent the shaft falling below its lower position.

A pair of controlling levers 22 are provided for supporting and moving each frame 7 these levers 22 being disposed at opposite sides of the latter and the levers 22 are pivotally connected at one end at 220 to a lug 23 upon the frame 7 (FIGURES 2 and 3) and at the other end are mounted upon fixed supports by pivots 24 (FIG- URE 2). The levers 22 associated with and disposed at opposite sides of each of half of the total number of frames 7 extend upwardly and the levers 22 associated with and disposed at opposite sides of each of the remaining frames 7 extend downwardly.

Each of the four levers 22 disposed at one side of one of the groups of four shafts 2 is adapted to be turned about its pivot by means of cams upon an endless chain, indicated in chain dotted lines at 26, of a width commensurate with the spacing of the shafts and of a length corresponding to the length of the pattern of the fabric being woven. The chain 26 is engaged with two sprockets 27, 28, 29 upon each of three horizontal shafts 30, 31, 32. Each of the four levers 22 disposed at the opposite side of the same set of four shafts 2 is adapted to be contacted and turned about its pivotal support by means of cams upon an endless control chain, indicated in chain dotted lines at 33. Chain 33 is engaged with two sprockets 34, 35, 36 upon each of three horizontal shafts 37, 38, 39.

Each of the levers 22 connected to the four frames 7 associated with the other four shafts is arranged to be turned about its pivotal support by means of an associated rotary cam. Thus, four eccentric cams 40 at one side of the set of frames 7 are rigidly mounted upon a horizontal shaft 41 extending below the shaft 30. Four eccentric cams 42 are rigidly mounted at the opposite side of the set of frames 7 upon a horizontal shaft 43 extending below the shaft 37.

Each lever 22 is furnished with a freely rotatable roller 25 for contact with the patterning means.

The shafts 30, and 43 are driven in the opposite direction to shafts 33 and 41 by intermeshed spur gears 44, 45, 46 and 47 (FIGURES 2 and 3) whereby the cams 40, 42 and the chains 26, 33 are synchronised with one another.

During each picking motion of the loom some of the shafts are in their upper positions and others are in their lower positions, the positions of the various shafts being variable as weaving proceeds to determined the pattern or weave. For example, in a dobby mechanism incorporating eight heald shafts, various combinations are possible of which two will now be cited by way of example. These are, an even number, such as 2 and 2 and an odd number such as 5 and 1 plus 1 and 1, making an 8 pick repeat. For the even 2 and 2 changes, each heald shaft rises on one yoke to its upper position and stays in that position for two picks, and after the shaft has been lowered again by the other yoke, it remains in its lower position for two picks and then rises on the first mentioned yoke, and so on. But if an odd number of changes is involved, each shaft rises on one yoke and is lowered by the same yoke. For example, in an 8 pick repeat, each shaft stays in its upper position for 5 picks and in its lower position for one pick, then rises for one pick and descends again for one pick, all of the up and down strokes in this case being effected by the same yoke.

The loom dobby mechanism of this example is eminently suited to the production of patterned woven webs in which the pattern is of a relatively long length, for example, up to say 300 picks. Patterning of the fabric is effected by selection of the four shafts 2 controlled by the chains 26, 33 and the chains are each of a length cornmensurate with the length of the pattern. The background of the fabric is produced upon the four shafts 2 controlled by the two sets of rotary cams 40, 42.

The latter may also be utilised to form simple patterns of short lengths, for example up to a length of 16 picks. Any repeat pattern which is divisible into 16, for example 2 and 2, 3 and 1, and 7 and 1, could be produced by the heald frames controlled by the rotary cams.

Because of the levers 22 associated with the two groups of frames 7 extend in opposite directions and and the rotary cams 40, 42 are disposed above the shafts 30, 33 carrying the sprockets of the chains, so that the adjacent rotary cams and chains overlap one another laterally, the

spacing of the frames 7 and hence of the shafts 2, is no more than would be required in a case where all eight frames 7 are controlled by two endless cam chains located at respectively opposite sides of the frames and each of a width to control all eight frames. Thus, the shedding of the warp threads effected by the dobby mechanism of this example is produced in the same space as (that is to say the length of the shed is no greater than the shed produced by), a mechanism in which all of the frames are controlled by endless cam chains. A high weaving rate is made possible without sacrificing quality of the weaving.

I claim:

1. A loom dobby of the kind comprising a set of vertically disposed and vertically slidable heald shafts, and means for selectively lifting the latter to raised positions, dropping them to low positions and allowing them to pase between strokes for variable lengths of time, all according to weaving and patterning requirements, wherein the improvement comprises in combination: two rows of drivers disposed at respectively opposite sides of the set of heald shafts, one driver of each row being associated with a relevant one of the heald shafts and each of the latter and its two associated drivers having complementary engageable and disengageable formations; two driving levers which are respectively engaged with the two rows of heald shaft drivers; a common pivot pin upon which the said two driving levers are mounted; cams for independently swinging the two driving levers up and down with strokes of the same extent but out of phase so that when one lever is located in its upper position the other is located in its lower position, and vice versa, these levers serving to reciprocate the drivers vertically in paths parallel to the paths of movement of the heald shafts; opposed control means oppositely operable at respectively opposite sides of the heald shafts and their drivers for selectively imparting to the latter positive movements transversely with respect to the heald shafts; to bring the aforesaid complementary formations into and out of engagement and so determine the individaul vertical movements of the said shafts and releasable locking means influenced by transverse movements of the drivers for holding heald shafts in their raised and in their low positions, at appropriate times, the whole being characterized by the absence of return springs.

2. A loom dobby according to claim 1, wherein the two drivers associated with each heald shaft are mounted on rods by which they are guided in their reciprocatory movements vertically, these rods being fixed in a frame which extends in a vertical plane coincident with the path of movement of the heald shaft and has in upper and lower portions thereof apertures through which the said shaft is slidable.

3. A loom dobby according to claim 2, wherein means for supporting and laterally moving each frame to engage or disengage either one or the other of the two drivers associated therewith consist of a pair of suitably shaped levers, disposed at opposite sides of the frame, and each pivotally connected at one end to the frame and pivotally connected at the other end to suitable supports.

4. A loom dobby according to claim 3, wherein the said levers are arranged to be turned to move the frame, by opposed and oppositely operable control means which are adapted to effect the required lateral movements of the frame in accordance with weaving requirements.

5. A loom dobby according to claim 4, wherein the control means comprises two endless chains furnished with prearranged cams and arranged to control each of some only of the levers at respectively opposite sides of the frames and hence some only of the heald shafts; two individual rotary cams arranged to control each of the remaining heald shafts and located at respectively opposite sides of the frames associated with the latter and provided respectively upon the relevant one of shafts carrying sprockets supporting the said endless chains.

6. A loom dobby according to claim 3, wherein the levers controlled by the rotary cam chains extend in opposite directions to those controlled by the rotary cams and the cam chains at opposite sides of the frames are engaged respectively with sprockets upon two horizontal drive shafts disposed below the shafts carrying the sprockets and driven with the latter.

7. A loom dobby according to claim 1, wherein the locking means relative to each heald shaft comprise complementary formations on the said shafts and the corre sponding frame, some of which formations are interengaged, when the shaft is to be held in either its raised or lowered positions to prevent movement thereof until the frame is moved laterally to release the locking means.

8. A loom dobby of the kind comprising a set of vertically disposed and vertically slidable heald shafts, and means for selectively lifting the latter to raised positions, dropping them to low positions and allowing them to pause between strokes for variable lengths of time, all according to weaving requirements, wherein the improvement comprises in combination: two rows of driving yokes disposed at respectively opposite sides of the heald shafts, the limbs of each of the yokes being shaped to engage two recesses formed in the edge of each heald shaft, One yoke of each roW being associated with a relevant one of the heald shafts; rods carrying said two yokes, by which they are guided in their reciprocatory movements vertically in a frame in which the said rods are fixed and which extends in a vertical plane coincident with the path of movement of the heald shaft, said frame having in upper and lower portions thereof apertures through which said shaft.

is slidable; two driving levers which pass between the limbs of all the rows of yokes at the relevant sides of the series of heald shafts; a common pivot pin upon which the said two driving levers are mounted; cams for inde pendently swinging the two driving levers up and down with strokes of the same extent but out of phase, so that when one lever is located in its upper position the other is located in its lower position, and vice versa, these levers serving to reciprocate the yokes vertically in paths parallel to the paths of movement of the heald shafts; opposed control means oppositely operable at respectively opposite sides of the frames for moving the latter laterally in one direction or the other from a neutral position in which neither of the associated two driving yokes is engaged with the corresponding heald shaft, the arrangement being such that the said two yokes may be alternately engaged with the heald shaft, to determine the individual vertical movements of the latter; and releasable locking means relative to each heald shaft, said means comprising appropriately spaced projections on the said shaft, which projections, when the shaft is to be held in either its raised or low positions, engage parts of the corresponding frame, the latter also being formed with slots such that, when the frame is laterally displaced in either direction from a neutral position to effect interengagement of one or other of the associated yokes with the shaft, the slots are brought into alignment with the projections on the shaft so that the latter is free to move into the other of its positions, the whole being characterized by the absence of return springs.

References Cited FOREIGN PATENTS 424,678 1947 Italy. 863,024 l/1953 Germany.

9,989 1884 Great Britain. 1,026,218 4/1966 Great Britain.

HENRY S. JAUDON, Primary Examiner. 

